[0001] Osteoporosis describes a group of diseases which arises from diverse etiologies,
but which are characterized by the net loss of bone mass per unit volume. The consequence
of this loss of bone mass and resulting bone fracture is the failure of the skeleton
to provide adequate support for the body. One of the most common types of osteoporosis
is associated with menopause. Most women lose from about 20% to about 60% of the bone
mass in the trabecular compartment of the bone within 3 to 6 years after the cessation
of menses. This rapid loss is generally associated with an increase of bone resorption
and formation. However, the resorptive cycle is more dominant and the result is a
net loss of bone mass. Osteoporosis is a common and serious disease among postmenopausal
women.
[0002] There are an estimated 25 million women in the United States alone who are afflicted
with this disease. The results of osteoporosis are personally harmful, and also account
for a large economic loss due to its chronicity and the need for extensive and long
term support (hospitalization and nursing home care) from the disease sequelae. This
is especially true in more elderly patients. Additionally, although osteoporosis is
generally not thought of as a life threatening condition, a 20% to 30% mortality rate
is related to hip fractures in elderly women. A large percentage of this mortality
rate can be directly associated with postmenopausal osteoporosis.
[0003] The most vulnerable tissue in the bone to the effects of postmenopausal osteoporosis
is the trabecular bone. This tissue is often referred to as spongy or cancellous bone
and is particularly concentrated near the ends of the bone (near the joints) and in
the vertebrae of the spine. The trabecular tissue is characterized by small osteoid
structures which interconnect with each other, as well as the more solid and dense
cortical tissue which makes up the outer surface and central shaft of the bone. This
interconnected network of trabeculae gives lateral support to the outer cortical structure
and is critical to the biomechanical strength of the overall structure. In postmenopausal
osteoporosis, it is primarily the net resorption and loss of the trabeculae which
leads to the failure and fracture of bone. In light of the loss of the trabeculae
in the postmenopausal woman, it is not surprising that the most common fractures are
those associated with bones which are highly dependent on trabecular support, for
example, the vertebrae, the neck of the weight-bearing bones such as the femur and
the forearm. Indeed, hip fracture, collies fractures, and vertebral crush fractures
are hallmarks of postmenopausal osteoporosis.
[0004] The most generally accepted method for the treatment of postmenopausal osteoporosis
is estrogen replacement therapy. Although therapy is generally successful, patient
compliance with the therapy is low, primarily because estrogen treatment frequently
produces undesirable side effects. An additional method of treatment would be the
administration of a bisphosphonate compound, such as, for example, Fosamax® (Merck
& Co., Inc.).
[0005] Throughout premenopausal time, most women have less incidence of cardiovascular disease
than men of the same age. Following menopause, however, the rate of cardiovascular
disease in women slowly increases to match the rate seen in men. This loss of protection
has been linked to the loss of estrogen and, in particular, to the loss of estrogen's
ability to regulate the levels of serum lipids. The nature of estrogen's ability to
regulate serum lipids is not well understood, but evidence to date indicates that
estrogen can up regulate the low density lipid (LDL) receptors in the liver to remove
excess cholesterol. Additionally, estrogen appears to have some effect on the biosynthesis
of cholesterol, and other beneficial effects on cardiovascular health.
[0006] It has been reported in the literature that serum lipid levels in postmenopausal
women having estrogen replacement therapy return to concentrations found in the premenopausal
state. Thus, estrogen would appear to be a reasonable treatment for this condition.
However, the side effects of estrogen replacement therapy are not acceptable to many
women, thus limiting the use of this therapy. An ideal therapy for this condition
would be an agent which regulates serum lipid levels in a manner analogous to estrogen,
but which is devoid of the side effects and risks associated with estrogen therapy.
[0007] EP 0 703 231 discloses 3-benzyl substituted benzo[b]thiophene derivatives. One of
the uses claimed for these compounds is in alleviating the symptoms of postmenopausal
syndrome.
[0008] EP 0 675 121 relates to processes and intermediates in the preparation of 3-benzoyl
substituted benzo[b]thiophene compounds.
[0009] The instant invention provides benzo[b]thiophene compounds, pharmaceutical formulations
thereof, and methods of using such compounds for inhibiting the above-mentioned pathologies.
[0010] The present invention relates to compounds of formula I

wherein:
R1 is -H, -OH, -O(C1-C4 alkyl), -OCOAr, -O(CO)OAr, where Ar is phenyl or substituted phenyl, -OCO(C1-C6 alkyl), -O(CO)O(C1-C6 alkyl), or
-OSO2(C2-C6 alkyl);
R2 is -H, -Cl, -F, -OH, -O(C1-C4 alkyl), -OCOAr, -O(CO)OAr, where Ar is phenyl or substituted phenyl, -OCO(C1-C6 alkyl), -O(CO)O(C1-C6 alkyl), or -OSO2(C2-C6 alkyl);
R3 is 1-piperidinyl, 1-pyrrolidinyl, methyl-1-pyrrolidinyl, dimethyl-1-pyrrolidinyl,
4-morpholino, dimethylamino, diethylamino, diisopropylamino, or 1-hexamethyleneimino;
R4 is -H, C1-C5 alkyl, -COAr, -(CO)H, -CO(C1-C6 alkyl), -SO2(C2-C6 alkyl), or -SO2Ar, where Ar is phenyl or substituted phenyl; and
n is 2 or 3;
or a pharmaceutically acceptable salt or solvate thereof.
[0011] Also provided by the present invention are intermediate compounds of formula II which
are useful for preparing the pharmaceutically active compounds of the present invention,
and are shown below:

wherein:
R1a is -H or -OR7 in which R7 is a hydroxy protecting group;
R2a is -H, -Cl, -F, or -OR7 in which R7 is a hydroxy protecting group;
R4a is -CO(C1-C4 alkyl) or -(CO)H; and
R6 is -H or R8, wherein R8 is a hydroxy protecting group which can be selectively removed in the presence of
-OR7.
[0012] Further, the present invention provides compounds of formula VII, which are useful
for the synthesis of the compounds of formula I:

wherein: R
1a, R
2a, R
4a, and n have their previous meanings and Q is a leaving group.
[0013] The present invention further relates to pharmaceutical formulations containing compounds
of formula I, and the use of such compounds for alleviating the symptoms of bone loss
or bone resorption, particularly osteoporosis, cardiovascular-related pathological
conditions, and the like.
[0014] General terms used in the description of compounds herein described bear their usual
meanings. For example, "C
1-C
6 alkyl" refers to straight or branched aliphatic chains of 1 to 6 carbon atoms including
methyl, ethyl, propyl, isopropyl, butyl, n-butyl, pentyl, isopentyl, hexyl, isohexyl,
and the like. Similarly, the term "-OC
1-C
4 alkyl" represents a C
1-C
4 alkyl group attached through an oxygen such as, for example, methoxy, ethoxy, n-propoxy,
isopropoxy, and the like. Of these C
1-C
4 alkoxy groups, methoxy is highly preferred.
[0015] The term "substituted phenyl" refers to a phenyl group having one or more substituents
selected from the group consisting of C
1-C
4 alkyl, -OC
1-C
4 alkyl, hydroxy, nitro, chloro, fluoro, or tri(chloro or fluoro)methyl.
[0016] The term "hydroxy protecting group" contemplates numerous functionalities used in
the literature to protect a hydroxyl function during a chemical sequence and which
can be removed to yield the phenol. Included within this group would be acyls, mesylates,
tosylates, benzyl, alkylsilyloxys, C
1-C
4 alkyls, and the like. Numerous reactions for the formation and removal of such protecting
groups are described in a number of standard works including, for example,
Protective Groups in Organic Chemistry, Plenum Press (London and New York, 1973); Green, T.W.,
Protective Groups in Organic Synthesis, Wiley, (New York, 1981); and
The Peptides, Vol. I, Schrooder and Lubke, Academic Press (London and New York, 1965). Methods
for removing preferred R
7 hydroxy protecting groups, particularly methyl and alkylsilyloxy, are essentially
as described in the Examples,
infra.
[0017] The term "leaving group (Q)" means a chemical entity which is capable of being displaced
by an amino function via an SN
2 reaction. Such reactions are well known in the art and such groups would include
halogens, mesylates, tosylates, and the like. A preferred leaving group would be bromo.
[0018] The term "inhibit" includes its generally accepted meaning which includes prohibiting,
preventing, restraining, and slowing, stopping, or reversing progression, severity,
or ameliorating a resultant symptom or effect.
[0019] The term "solvate" represents an aggregate that comprises one or more molecules of
the solute, such as a formula I compound, with one or more molecules of solvent.
[0020] The compounds of this invention are derivatives of centrally located carbon, for
example, the "-CO-","-CHOH-", or "-CH
2-" moiety in formula I are therefore derivatives of methanones, methanols, or methanes.
For example, a compound of A-CO-B, would be named [A][B]methanone. Further, the compounds
of formula I are derivatives of benzo[b]thiophene which is named and numbered according
to the Ring Index, The American Chemical Society, as follows:

[0021] Preferred compounds of the present invention are 2-(4-hydroxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]amino]-6-hydroxybenzo[b]thiophene
hydrochloride and 2-(4-methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]amino]-6-methoxybenzo[b]thiophene
di-hydrochloride.
[0022] Several synthetic pathways are available for preparing the compounds of the instant
invention. The first synthetic route is illustrated in Scheme I, below. The starting
material for one route for preparing compounds of formula I of the present invention,
compounds of formula III, are prepared essentially as described by Jones
et al. in U.S. Pat. Nos. 4,418,068, and 4,133,814. Formula III has the following structure:

wherein R
1a and R
2a are as defined above.
[0023] For compounds of formula III, a preferred R
7 substituent is methyl or methoxymethyl. Compounds in which R
1a and R
2a each are methoxy, as well as other derivatives, are prepared via the procedure described
in Jones
et al.,
supra.
[0024] The first steps of the present process for preparing certain compounds of formula
I include selectively placing a leaving group at the 3 position of a formula III compound,
coupling the reaction product of the first step with a 4-(protected-hydroxy)phenylacylamide
(formula V), and removing the hydroxy protecting group to generate a phenol of compound
IIb. The process is depicted in Scheme I below.

[0025] In the first step of Scheme I, an appropriate leaving group is selectively placed
at the 3-position of the formula III starting material via standard procedures. Appropriate
R
9 leaving groups include sulfonates such as methanesulfonate, 4-bromobenzenesulfonate,
toluenesulfonate, ethanesulfonate, isopropanesulfonate, 4-methoxybenzenesulfonate,
4-nitrobenzenesulfonate, 2-chlorobenzenesulfonate, triflate, and the like, halogens
such as bromo, chloro, and iodo, and other related leaving groups. However, to insure
proper placement of the leaving group, the named halogens are preferred, and bromo
is especially preferred.
[0026] The present reaction is carried out using standard procedures. For example, when
the preferred halogenating agents are used, an equivalent of such a halogenating agent,
preferably bromine, is reacted with an equivalent of the formula III substrate, in
the presence of a suitable solvent such as, chloroform or acetic acid. The reaction
is run at a temperature from about 40° C to about 80° C and is usually complete in
one to six hours.
[0027] The reaction product from the above process step, a compound of formula IV, is then
reacted with a 4-(protected-hydroxy)phenylakylamide (formula V), for example, in which
R
4a is -(CO)H or -CO(C
1-C
4 alkyl), to form compounds of formula II in which R
8 is a selectively- removable hydroxy protecting group. Generally, the 4-hydroxy protecting
moiety of the phenol may be any known protecting group which can be selectively removed
without removing the R
7, when present, moiety of a formula II compound. A preferred R
8 protecting group is benzyl. The 4-(protected-hydroxy)phenylalkylamides are known
compounds and can be prepared via standard procedures. For example, a preferred reagent,
for example, 4-benzyloxyphenyl acetamide, may be synthesized from commericially available
4-benzyloxyaniline and acetic anhydride by methods known in the art.
[0028] This coupling reaction of IV and V is known in the art as an Ullman-type reaction,
and various standard procedures are listed. [
See, for example,
Advanced Organic Chemistry: Reactions, Mechanisms,
and Structure, Fourth Edition, 3-16, (J. March, ed., John Wiley & Sons, Inc. 1992); Jones,
C.D.,
J. Chem. Soc. Perk. Trans. I, 4 :407 (1992)].
[0029] Although several variations of the standard Ullman-type reactions were attempted,
for example, reacting an aniline or an anilinosulfamide with aryl bromide in the presence
of a copper catalyst, only a variant known as a Goldberg reaction was successful.
Details of this reaction are given below.
[0030] In general, equivalent amounts of the two aryl substrates, in the presence of up
to an equimolar amount of a copper(I) oxide catalyst and an appropriate solvent, are
heated to reflux under an inert atmosphere. Examples of a suitable catalytic copper
(I) salt would include but not be limited to Cu
2O, CuI, and Cu
2CO
3. Preferably, an equivalent of a formula IV compound in which R
9 is bromo is reacted with an equivalent amount of 4-benzyloxyphenylacetamide in the
presence of an equivalent of cuprous oxide.
[0031] Appropriate solvents for this reaction are those solvents or mixture of solvents
which remain inert throughout the reaction. Typically, organic bases, particularly
a hindered base such as, for example, 2,4,6-collidine, are preferred solvents.
[0032] The temperature employed in this step should be sufficient to effect completion of
this coupling reaction, and will influence the amount of time required therefor. When
the reaction mixture is heated to reflux under an inert atmosphere such as nitrogen.
The reaction is usually complete in twenty to one hundred-twenty hours.
[0033] Following the coupling reaction, which forms a formula IIa compound, formula IIb
compounds are prepared, via well known reduction procedures, by selectively removing
the R
6 hydroxy protecting group. It is imperative that the selected procedure will not affect,
when present, the R
7 hydroxy protecting group.
[0034] When R
8 is the preferred benzyl moiety, and R
7, when present, is methyl, the present process step is carried out via standard hydrogenolysis
procedures. Typically, the formula IIa substrate is added to a suitable solvent or
mixture of solvents, followed by the addition of a proton donor to accelerate the
reaction and an appropriate hydrogenation catalyst.
[0035] Appropriate catalysts include noble metals and oxides such as palladium, platinum,
and rhodium oxide on a support such as carbon or calcium carbonate. Of these, palladium-on-carbon,
particularly 10% palladium-on-carbon, is preferred.
[0036] Solvents for this reaction are those solvents or mixture of solvents which remain
inert throughout the reaction. Typically, ethylacetate and C
1-C
4 aliphatic alcohols, particularly ethanol, is preferred.
[0037] For the present reaction, hydrochloric acid serves as an adequate and preferred proton
donor.
[0038] When run at ambient temperature and at a hydrogen pressure ranging from about 30
psi to about 50 psi, the present reaction runs quite rapidly. Progress of this reaction
may be monitored by standard chromatographic techniques such as thin layer chromatography.
[0039] Compounds of formula IIa and IIb are encompassed within the genus described herein
as formula II compounds, and are useful for preparing the pharmaceutically active
compounds of formula I.
[0040] Examples of the compounds of formula II include, but are not limited to:
2-(4-methoxyphenyl)-3-[N-(4-hydroxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
2-phenyl-3-[N-(4-hydroxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
2-(4-fluorophenyl)-3-[N-(4-hydroxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
2-(4-chlorophenyl)-3-[N-(4-hydroxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-(4-benzyloxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
2-phenyl-3-[N-(4-benzyloxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-(4-hydroxyphenyl)propanoylamido]-6-methoxy-benzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-(4-benzyloxyphenyl)butanoylamido]-6-methoxy-benzo[b]thiophene
2-(4-chorophenyl)-3-[N-(4-benzyloxyphenyl)acetamido]benzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-(4-hydroxyphenyl)acetamido]benzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-(4-benzyloxyphenyl)acetamido]benzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-(4-benzyloxyphenyl)formylamido]benzo[b]thiophene
2-(4-fluorophenyl)-3-[N-(4-benzyloxyphenyl)propanoylamido]benzo[b]thiophene, and the
like.
[0041] The compounds of formula IIb may be converted into the compounds of formula Ia by
one of two different synthetic routes, which are illustrated in Scheme II, below.
[0042] The first method is the direct conversion of IIb to Ia by using a reagent of formula
VI:
R
3 - (CH
2)
n - Q VI
wherein R
3 and n are as defined above, and Q is a leaving group, such as a bromo or chloro moiety.

[0043] The direct alkylation process, shown in Scheme II, is carried out via standard procedures.
Compounds of formula VI are commercially available or are prepared by means well known
to one of ordinary skill in the art. Preferably, the hydrochloride salt of a formula
VI compound, particularly preferred is 2-chloroethylpiperidine hydrochloride.
[0044] Generally, at least about 1 equivalent of formula IIb substrate are reacted with
2 equivalents of a formula VI compound in the presence of at least about 4 equivalents
of an alkali metal carbonate, preferably cesium carbonate, and an appropriate solvent.
[0045] Solvents for this reaction are those solvents or mixtures of solvents which remain
inert throughout the reaction. N,N-dimethylformamide, especially the anhydrous form
thereof, is preferred.
[0046] The temperature employed in this step should be sufficient to effect completion of
this alkylation reaction. Typically, ambient temperature is sufficient and preferred.
[0047] The present reaction preferably is run under an inert atmosphere, particularly nitrogen.
[0048] Under the preferred reaction conditions, this reaction will run to completion in
about 16 to about 20 hours. Of course, the progress of the reaction can be monitored
via standard chromatographic techniques.
[0049] The second method for preparing compounds of formula Ia from a formula IIb compound
is to proceed through an intermediate compound (formula VII) in a two-step sequence
(see Scheme II,
supra). A compound of formula IIb is reacted with an excess of an alkylating agent of the
formula
Q - (CH
2)
n - Q'
wherein Q and Q' each are the same or different leaving groups, in an alkali solution.
Appropriate leaving groups can be, for example, chloro, bromo, mesylates, tosylates
and the like. A preferred alkali solution for this alkylation reaction contains potassium
carbonate in an inert solvent such as, for example, methylethyl ketone (MEK) or DMF.
In this solution, the 4-hydroxy group of the phenyl moiety of a formula IIb compound
exists as a phenoxide ion which displaces one of the leaving groups of the alkylating
agent.
[0050] This reaction proceeds rapidly when the alkali solution containing the reactants
and reagents is brought to reflux and allowed to run to completion. When using MEK
as the preferred solvent, reaction times run from about 6 hours to about 20 hours.
[0051] The compounds of formula VII are useful in the synthesis of the compounds of formula
I. Compounds of formula VII would include, but are not limited to:
2-(4-methoxyphenyl)-3-[N-[4-(2-bromoethoxy)phenyl]acetylamido]-6-methoxybenzo[b]thiophene
2-phenyl-3-[N-[4-(2-bromoethoxy)phenyl]acetylamido]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-(2-bromoethoxy)phenyl]acetylamido]benzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-(3-bromopropoxy)phenyl]acetylamido]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-(2-chloroethoxy)phenyl]acetylamido]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-(2-tosylethoxy)phenyl]acetylamido]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-(2-bromoethoxy)phenyl]butanoylamido]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-(2-bromoethoxy)phenyl]formylamido]-6-methoxybenzo[b]thiophene,
and the like.
[0052] The reaction product (formula VII) from this step is then reacted with an amine (R
3), for example, 1-piperidine, 1-pyrrolidine, methyl-1methyl-1-pyrrolidine, dimethyl-1-pyrrolidine,
4-morpholine, dimethylamine, diethylamine, diisopropylamine, or 1-hexamethyleneimine,
via standard techniques, to form compounds of formula Ia. Preferably, the hydrochloride
salt of piperidine is reacted with a compound of formula VII in an inert solvent,
such as anhydrous DMF, and heated to a temperature in the range from about 60° C to
about 110° C. When the mixture is heated to a preferred temperature of about 90° C,
the reaction only takes about 30 minutes to about 1 hour. However, changes in the
reaction conditions will influence the amount of time this reaction needs to be run
for completion. Of course, the progress of this reaction step may be monitored via
standard chromatographic techniques.
[0053] Conversion of the compounds of formula Ia to other compounds of formula I is shown
in Scheme III and may involve: the removal of the N-acyl group to form the diaryl
amino series (Ib), removal and re-introduction to form another acyl or a sulfonyl
series (Ic), or the reduction of the N-acyl to a N-alkyl series (Id).

[0054] Removal of the N-acyl group from a compound of formula Ia can readily be accomplished
by either acid or base hydrolysis to form a compound of Ib, where R
1a, R
2a, R
3, and n have their previous meanings. The preferred method involves heating a formula
Ia compound in a solution of alcohol and concentrated alkoxide. Typically, EtOH is
used as the organic solvent and 50% NaOH solution is used as the source of base. The
substrate is dissolved in an equal mixture of the alcohol and base and heated to the
reflux temperature of the combined solvent. The reaction usually requires between
6 and 24 h for completion.
[0055] Compounds of formula Ib are pharmaceutically active for the methods herein described.
Accordingly, such compounds are encompassed by the definition herein of compounds
of formula I.
[0056] Additionally, compounds of formula Ib may serve as substrates for preparing compounds
of formula Ic where R
1a, R
2a, R
3, and n have their previous meanings and R
4c is -CO(C
1-C
6 alkyl), -(CO)H, -COphenyl, -SO
2phenyl, or -SO
2(C
2-C
6alkyl). To form these compounds, the nitrogen is either acylated or sulfonated. This
can readily be accomplished by a variety of acylation and alkylation methods that
are well known in the art. For further methods on such acylations and sulfonations,
the discussion on derivatization of the phenols (see below) is applicable.
[0057] The compounds of formula Ia may also be converted to the compounds of formula Id,
where R
1a, R
2a, R
3, and n have their previous meanings and R
4b is C
1-C
5 alkyl. This transformation may be achieved by the reduction of the amide carbonyl
in Ia to its corresponding methylene with a reducing reagent such as LAH. These reductions
are known in the art and are usually carried out in inert solvents such as anhydrous
THF, ether, and the like. These reactions are run with an excess of the reducing reagent
and at temperatures of -50 to 30° C under a nitrogen atmosphere. Reactions are normally
complete within two to twenty-four hours, standard techniques such as tlc may be used
to monitor the extent of the reaction.
[0058] The compounds of formula Ia, Ib, Ic, and Id are pharmacologically active for the
methods herein described, and are encompassed in formula I as defined herein. Additionally,
compounds of formula Ia-d may serve as substrates for other compounds of formula I,
such as, for exmaple, compounds where R
1a and R
2a are converted to R
1 and R
2, respectively.
[0059] Preferred compounds of formula I are obtained by cleaving the R
7 hydroxy protecting group, when present, of formulae Ia-d compounds via well known
procedures. Numerous reactions for the formation and removal of such protecting groups
are described in a number of standard works including, for example,
Protective Groups in Organic Chemistry, Plenum Press (London and New York, 1973); Green, T.W.,
Protective Groups in Organic Synthesis, Wiley, (New York, 1981); and
The Peptides, Vol. I, Schrooder and Lubke, Academic Press (London and New York, 1965). Methods
for removing the preferred R
7 hydroxy protecting group, methyl, is essentially as described in the Examples,
infra
[0060] Other preferred compounds of formula I are prepared by converting 6- and/or 4'-position
hydroxy moieties, when present, to a moiety of the formula -O-CO-(C
1-C
6 alkyl), -OCOC
6H
5, -O(CO)O(C
1-C
6 alkyl) or -O-SO
2-(C
2-C
6 alkyl) via well known procedures. Such methods are described in US Pat. Nos. 5,393,763
and 5,482,949 the disclosures of which are herein incorporated by reference.
[0061] For example, when an -O-CO(C
1-C
6 alkyl) group is desired, a mono- or dihydroxy compound of formula Ia-d is reacted
with an agent such as acyl chloride, bromide, cyanide, or azide, or with an appropriate
anhydride or mixed anhydride. The reactions are conveniently carried out in a basic
solvent such as pyridine, lutidine, quinoline or isoquinoline, or in a tertiary amine
solvent such as triethylamine, tributylamine, methylpiperidine, and the like. The
reaction also may be carried out in an inert solvent such as ethyl acetate, dimethylformamide,
dimethylsulfoxide, dioxane, dimethoxyethane, acetonitrile, acetone, methyl ethyl ketone,
and the like, to which at least one equivalent of an acid scavenger (except as noted
below), such as a tertiary amine, has been added. If desired, acylation catalysts
such as 4-dimethylaminopyridine or 4-pyrrolidinopyridine may be used.
See, for example, Haslam,
et al., Tetrahedron, 36: 2409-2433 (1980).
[0062] The present reactions are carried out at moderate temperatures, in the range from
about -25° C to about 100° C, frequently under an inert atmosphere such as nitrogen
gas. However, ambient temperature is usually adequate for the reaction to run.
[0063] Side-reactions of acylating the bis-aryl nitrogen (formula Ib compounds) may be reduced
by not using excess amounts of acylating reagent and using lower temperatures. Undesired
isomers may be removed by chromatography on silica gel eluted with mixtures of solvents,
such as, MeOH-CHCl
3 (1:99) (v/v) or EtOAc-hexane mixtures.
[0064] Acylation of a 6-position and/or 4'-position hydroxy group also may be performed
by acid-catalyzed reactions of the appropriate carboxylic acids in inert organic solvents.
Acid catalysts such as sulfuric acid, polyphosphoric acid, methanesulfonic acid, and
the like are used.
[0065] The aforementioned R
1 and/or R
2 groups of formula Ia-d compounds also may be provided by forming an active ester
of the appropriate acid, such as the esters formed by such known reagents such as
dicyclohexylcarbodiimide, acylimidazoles, nitrophenols, pentachlorophenol, N-hydroxysuccinimide,
and 1-hydroxybenzotriazole.
See, for example,
Bull. Chem. Soc. Japan, 38:1979 (1965), and
Chem. Ber., 788 and 2024 (1970).
[0066] Each of the above techniques which provide -O-CO-(C
1-C
6 alkyl) moieties are carried out in solvents as discussed above. Those techniques
which do not produce an acid product in the course of the reaction, of course, do
not call for the use of an acid scavenger in the reaction mixture.
[0067] When a formula Ia-d compound is desired in which the 6-and/or 4'-position hydroxy
group of a formula I compound is converted to a group of the formula -O-SO
2-(C
2-C
6 alkyl), the mono- or dihydroxy compound is reacted with, for example, a sulfonic
anhydride or a derivative of the appropriate sulfonic acid such as a sulfonyl chloride,
bromide, or sulfonyl ammonium salt, as taught by King and Monoir,
J. Am. Chem. Soc., 97 :2566-2567 (1975). The dihydroxy compound also can be reacted with the appropriate
sulfonic anhydride or mixed sulfonic anhydrides. Such reactions are carried out under
conditions such as were explained above in the discussion of reaction with acid halides
and the like.
[0068] The compounds of formula Ia-d, their phenolic hydroxyl compounds, and their corresponding
derivatized phenols, combined, constitute the compounds of formula I of the current
invention.
[0069] Examples of the compounds of formula I include, but are not limited to:
2-(4-methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-methoxybenzo[b]thiophene
2-(4-hydroxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-hydroxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-hydroxybenzo[b]thiophene
2-(4-hydroxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]amino]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]-N-ethylamino]-6-methoxybenzo
[b]thiophene
2-(4-Methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]propanoylamido]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-[3-(1-piperidinyl)propoxy]phenyl]acetamido]benzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-[2-(1-pyrrolidinyl)ethoxy]phenyl]amino]-6-methoxybenzo[b]thiophene
2-(4-chlorophenyl)-3-[N-[4-[3-(1-hexamethylene)propoxy]phenyl]butanoylimido]-6-methoxybenzo[b]thiophene
2-phenyl-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]-N-methylamino]benzo[b]thiophene
2-(4-chlorophenyl)-3-[N-[4-[3-(1-pyrrolidinyl)propoxy]phenyl]-N-butylamino]-6-hydroxybenzo[b]thiophene
2-(4-acetyloxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-methoxybenzo[b]thiophene
2-(4-methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-n-butylsulfonyloxybenzo[b]thiophene
2-phenyl-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-benzoyloxybenzo[b]thiophene
2-(4-benzoyloxyphenyl)-3-[N-[4-[3-(1-piperidinyl)propoxy]phenyl]acetamido]-6-methoxybenzo[b]thiophene
2-(4-benzoyloxyphenyl)-3-[N-[4-(3-(1-hexamethyleneimino)propoxy]phenyl]-N-2-butylamino]-6-methoxybenzo[b]thiophene
2-[4-(4-methoxybenzoyloxy)phenyl]-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]-N-methylamino]-6-methoxybenzo[b]thiophene,
and the like.
[0070] Although the free-base form of formula I compounds can be used in the methods of
the instant invention, it is preferred to prepare and use a pharmaceutically acceptable
salt form. The term "pharmaceutically acceptable salt" refers to either acid or base
addition salts which are known to be non-toxic and are commonly used in the pharmaceutical
literature. The pharmaceutically acceptable salts generally have enhanced solubility
characteristics compared to the compound from which they are derived, and thus are
often more amenable to formulation as liquids or emulsions. The compounds used in
the methods of this invention primarily form pharmaceutically acceptable acid addition
salts with a wide variety of organic and inorganic acids, and include the physiologically
acceptable salts which are often used in pharmaceutical chemistry. Such salts are
also part of this invention.
[0071] Typical inorganic acids used to form such salts include hydrochloric, hydrobromic,
hydroiodic, nitric, sulfuric, phosphoric, hypophosphoric, and the like. Salts derived
from organic acids, such as aliphatic mono and dicarboxylic acids, phenyl-substituted
alkanoic acids, hydroxyalkanoic and hydroxyalkandioic acids, aromatic acids, aliphatic
and aromatic sulfonic acids, may also be used. Such pharmaceutically acceptable salts
thus include acetate, phenylacetate, trifluoroacetate, acrylate, ascorbate, benzoate,
chlorobenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, methylbenzoate,
o-acetoxybenzoate, naphthalene-2-benzoate, bromide, isobutyrate, phenylbutyrate, β-hydroxybutyrate,
butyne-1,4-dioate, hexyne-1,4-dioate, caproate, caprylate, chloride, cinnamate, citrate,
formate, fumarate, glycolate, heptanoate, hippurate, lactate, malate, maleate, hydroxymaleate,
malonate, mandelate, mesylate, nicotinate, isonicotinate, nitrate, oxalate, phthalate,
terephthalate, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate,
pyrrophosphate, propiolate, propionate, phenylpropionate, salicylate, sebacate, succinate,
suberate, sulfate, bisulfate, pyrosulfate, sulfite, bisulfite, sulfonate, benzenesulfonate,
p-bromophenylsulfonate, chlorobenzenesulfonate, ethanesulfonate, 2-hydroxyethanesulfonate,
methanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate,
p-toluenesulfonate, xylenesulfonate, tartarate, and the like. A preferred salt is the
hydrochloride salt.
[0072] The pharmaceutically acceptable acid addition salts are typically formed by reacting
a compound of formula I with an equimolar or excess amount of acid. The reactants
are generally combined in a mutual solvent such as diethyl ether or ethyl acetate.
The salt normally precipitates out of solution within about one hour to 10 days and
can be isolated by filtration, or the solvent can be stripped off by conventional
means. The instant invention further provides for pharmaceutically acceptable formulations
for administering to a mammal, including humans, in need of treatment, which comprises
an effective amount of a compound of formula I and a pharmaceutically acceptable diluent
or carrier.
[0073] As used herein, the term "effective amount" means an amount of compound of the instant
invention which is capable of inhibiting, alleviating, ameliorating, treating, or
preventing further symptoms in mammals, including humans, suffering from bone loss
or bone resorption, particularly osteoporosis, and cardiovascular-related pathological
conditions including hyperlipidemia, and other cardiovascular pathologies.
[0074] In the case of estrogen-dependent cancers, the term "effective amount" means the
amount of compound of the instant invention which is capable of alleviating, ameliorating,
inhibiting cancer growth, treating, or preventing the cancer and/or its symptoms in
mammals, including humans.
[0075] By "pharmaceutically acceptable formulation" it is meant that the carrier, diluent,
excipients and salt must be compatible with the active ingredient (a compound of formula
I) of the formulation, and not be deleterious to the recipient thereof. Pharmaceutical
formulations can be prepared by procedures known in the art. For example, the compounds
of this invention can be formulated with common excipients, diluents, or carriers,
and formed into tablets, capsules, and the like. Examples of excipients, diluents,
and carriers that are suitable for such formulations include the following: fillers
and extenders such as starch, sugars, mannitol, and silicic derivatives; binding agents
such as carboxymethyl cellulose and other cellulose derivatives, alginates, gelatin,
and polyvinyl pyrrolidone; moisturizing agents such as glycerol; disintegrating agents
such as agar agar, calcium carbonate, and sodium bicarbonate; agents for retarding
dissollution such as paraffin; resorption accelerators such as quaternary ammonium
compounds; surface active agents such as cetyl alcohol, glycerol monostearate; adsorptive
carriers such as kaolin and bentonite; and lubricants such as talc, calcium and magnesium
stearate and solid polyethylene glycols. Final pharmaceutical forms may be: pills,
tablets, powders, lozenges, syrups, aerosols, saches, cachets, elixirs, suspensions,
emulsions, ointments, suppositories, sterile injectable solutions, or sterile packaged
powders, and the like, depending on the type of excipient used.
[0076] Additionally, the compounds of this invention are well suited to formulation as sustained
release dosage forms. The formulations can also be so constituted that they release
the active ingredient only or preferably in a particular part of the intestinal tract,
possibly over a period of time. Such formulations would involve coatings, envelopes,
or protective matrices which may be made from polymeric substances or waxes.
[0077] The particular dosage of a compound of formula I required to treat, inhibit, or prevent
the symptoms and/ or disease of a mammal, including humans, suffering from the above
maladies according to this invention will depend upon the particular disease, symptoms,
and severity. Dosage, routes of administration, and frequency of dosing is best decided
by the attending physician. Generally, accepted and effective doses will be from 15mg
to 1000mg, and more typically from 15mg to 80mg, from one to three times per day.
Such dosages will be administered to a patient in need thereof, for at least one month,
and typically for six months, or chronically.
[0078] The formulations which follow are given for purposes of illustration and are not
intended to be limiting in any way. The total active ingredients in such formulations
comprises from 0.1% to 99.9% by weight of the formulation. The term "active ingredient"
means a compound of formula I.
| Formulation 1: Gelatin Capsules |
| Ingredient |
Quantity (mg/capsule) |
| Active Ingredient |
0.1-1000 |
| Starch NF |
0-500 |
| Starch flowable powder |
0-500 |
| Silicone fluid 350 centistokes |
0-15 |
The ingredients are blended, passed through a 3,5·10
-4 m aperture sieve (No. 45 mesh U.S. sieve), and filled into hard gelatin capsules.
| Formulation 2: Tablets |
| Ingredient |
Quantity (mg/tablet) |
| Active Ingredient |
2.5-1000 |
| Starch |
10-50 |
| Cellulose, microcrystalline |
10-20 |
| Polyvinylpyrrolidone (as 10% solution in water) |
5 |
| Sodium carboxymethylcellulose |
5 |
| Magnesium stearate |
1 |
| Talc |
1-5 |
[0079] The active ingredient, starch, and cellulose are passed through a 3,5·10
-4 m aperture sieve (No. 45 mesh U.S. sieve) and mixed thoroughly. The solution of polyvinylpyrrolidone
is mixed with the resultant powders which are then passed through a 1,425·10
-3 m aperture sieve (No. 14 mesh U.S. sieve). The granules thus produced are dried at
50-60 °C and passed through a 1.10
-3 m aperture sieve (No. 18 mesh U.S. sieve). The sodium carboxymethylcellulose, magnesium
stearate, and talc, previously passed through a 2,5·10
-4 m aperture sieve (No. 60 mesh U.S. sieve), are added to the above granules and thoroughly
mixed. The resultant material is compressed in a tablet forming machine to yield the
tablets.
| Formulation 3: Aerosol |
| Ingredient |
Weight % |
| Active Ingredient |
0.25 |
| Ethanol |
29.75 |
| Propellant 22 (Chlorodifluoromethane) |
70.00 |
| Total |
100.00 |
[0080] The active ingredient is mixed with ethanol and the mixture added to a portion of
the propellant 22, cooled to -30 °C and transferred to a filling device. The required
amount is then fed to a stainless steel container and diluted with the remainder of
the propellant. The valve units are then fitted to the container.
| Formulation 4: Suppositories |
| Ingredient |
Weight |
| Active ingredient |
150 mg |
| Saturated fatty acid |
glycerides 3000mg |
[0081] The active ingredient is passed through a 2,5·10
-4 m aperture sieve (No. 60 mesh U.S. sieve) and suspended in the fatty acid glycerides
which had previously heated to their melting point. The mixture is poured into a suppository
mold and allowed to cool.
| Formulation 5: Suspension |
| Suspensions each containing 0.1-1000 mg of a compound of formula I per 5 mL dose. |
| Ingredient |
Weight |
| Active Ingredient |
0.1-1000 mg |
| Sodium carboxymethyl cellulose |
50 mg |
| Syrup |
1.25 mL |
| Benzoic acid solution (0.1M) |
0.10 mL |
| Flavor |
q.v. |
| Color |
q.v. |
| Purified water to total |
Total 5 mL |
[0082] A compound of formula I is passed through a 3,5·10
-4 m aperture sieve (No. 45 mesh U.S. sieve) and mixed with the sodium carboxymethyl
cellulose and syrup to form a smooth paste. The benzoic acid solution, flavor, and
color diluted in water are added and mixture stirred thoroughly. Additional water
is added to bring the formulation to final volume.
[0083] The following Examples and Preparations are provided to better elucidate the practice
of the instant invention. All publications and patent applications mentioned in the
specification are indicative of the level of those skilled in the art to which this
invention pertains.
[0084] NMR data for the following Examples were generated on a GE 300 MHz NMR instrument,
and anhydrous CDCl
3 was used as the solvent unless otherwise indicated. Field strength for
13C NMR spectra was 75.5 MHz, unless otherwise indicated.
Preparation 1
2- (4-Methoxyphenyl) -3-bromo-6-methoxybenzo[b]thiophene
[0085] To a solution of 2-(4-methoxyphenyl)-6-methoxybenzo[b]thiophene (27.0 g, 100 mmol)in
1.10 L of chloroform at 60° C was added bromine (15.98 g, 100 mmol) dropwise dissolved
in 200 mL of chloroform. After the addition was complete, the reaction was cooled
to room temperature, and the solvent removed
in vacuo to provide 34.2 g (100%) of 2-(4-methoxyphenyl)-3-bromo-6-methoxybenzo[b]thiophene
as a white solid. mp 83-85° C.
1H NMR (DMSO-
d6) d 7.70-7.62 (m, 4H), 7.17 (dd, J = 8.6, 2.0 Hz, 1H), 7.09 (d, J = 8.4 Hz, 2H). FD
mass spec: 349, 350.
Anal.
Calcd. for C
16H
13BrO
2S: C, 55.03; H, 3.75. Found: C, 54.79; H, 3.76.
Preparation 2
2-(4-Methoxyphenyl)-3-[N-(4-benzyloxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
[0086] To a solution of 2-(4-methoxyphenyl)-3-bromo-6-methoxybenzo[b]thiophene (34.20 g,
0.098 mol) and N-4-benzyloxyphenylacetamide (23.7 g, 0.098 mol) in 100 mL of 2,4,6-collidine
under N
2 was added Cu
2O (14.0 g, 0.098 mol). The resulting mixture was heated to reflux for 72 h. Upon cooling.
the reaction was diluted with CH
2Cl
2 and the precipated solids were removed by filtration. The filtrate was concentrated
in vacuo, and the residue dissolved in EtOAc. The organic was then extracted several times
with 5.0 N HCl. The organic was dried (Na
2SO
4) and concentrated
in vacuo to a solid. Chromatography (SiO
2, CHCl
3) provided 2.43 g (5%) of 2-(4-methoxyphenyl]-3-[N-(4-benzyloxyphenyl]acetamido]-6-methoxy-benzo[b]thiophene
as an amber foam.
1H NMR (DMSO-
d6) d (doubling due to amide rotamers) 7.70-6.80 (m, 16H), 4.90 (bs, 2H), 3.78-3.75
(m, 6H), 2.11 and 1.78 (s, 3H). FD mass spec: 509.
Preparation 3
2-(4-Methoxyphenyl)-3-[N-(4-hydroxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
[0087] 2-(4-Methoxyphenyl)-3-[N-(4-benzyloxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
(2.43 g, 4.77 mmol) was dissolved in 50 mL of 1:1 EtOH/EtOAc containing 5% con. HCl.
To this solution was added 1.0 g of 5% Pd/C. The resulting mixture was hydrogenated
at 275,8 kPa (40 psi) for 4 h. The mixture was then filtered through Celite to remove
the catalyst. The filtrate was concentrated in vacuo to a semi-solid. Chromatograhy
(SiO
2, CHl
3) provided 1.32 g (83%) of 2-(4-methoxyphenyl)-3-[N-(4-hydroxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
as an amber foam.
1H NMR (DMSO-
d6) d (doubling due to amide rotamers) 9.53 and 9.36 (s, 1H), 7.62-6.51 (m, 11 H), 3.78
and 3.58 (s, 6H), 2.01 and 1.76 (s, 3H). FD mass spec: 419.
Anal. Calcd. for C
24H
21NO
4S•0.19 CHCl
3: C, 65.71; H, 4.83; N, 3.17. Found: C, 65.80; H, 4.70; N, 3.01.
Example 1
2- (4-Methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-methoxybenzo[b]thiophene
[0088] To a solution of 2-(4-methoxyphenyl)-3-[N-(4-hydroxyphenyl)acetamido]-6-methoxy-benzo[b]thiophene
(1.31 g, 3.13 mmol) and Cs
2CO
3 (4.10 g, 12.50 mmol) in 15 mL of anhydrous DMF was added 2-chlorethylpiperidine hydrochloride
(1.15 g, 6.26 mmol). The resulting mixture was stirred vigorously at room temperature
for 5 h. The reaction mixture was diluted with 200 mL of H
2O, and then extracted several times with EtOAc. The combined organic was then washed
with H
2O several times and then dried (Na
2SO
4), Concentration in vacuo provided an oil. Chromatography (1% CH
3OH/CHCl
3, SiO
2) provided 1.49 g (90%) of 2-(4-methoxyphenyl-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-methoxybenzo[b]thiophene
as an amber oil.
1H NMR (DMSO-
d6) d (doubling due to amide rotamers) 7.66-6.70 (m, 11 H), 3.93 (m, 2H) 3.78 and 3.58
(s, 6H), 2.8-2.30 (m, 6H), 2.01 and 1.78 (s, 3H), 1.52-1.11 (m, 6H). FD mass spec:
530.
Anal. Calcd. for C
31H
34N
2O
4S: C, 70.16; H, 6.46; N, 5.28. Found: C, 70.33; H, 6.34; N, 5.35.
Example 2
2-(4-Methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]amino]-6-methoxybenzo[b]thiophene
Di-Hydrochloride
[0089] To a solution of 2-(4-methoxyphenyl-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]acetamido]-6-methoxybenzo[b]thiophene
1.49 g, 2.80 mmol) in 10 mL of absolute EtOH was added 10 mL of 50% NaOH solution.
The resulting mixture was heated to reflux for 18 h. Upon cooling, the mixture was
diluted with 200 mL of H
2O. The aqueous was then extraced with EtOAc (3 x 100 mL). The organic was combined,
washed with brine, then dried (Na
2SO
4). Concentration
in vacuo provided a foam that was chromatographed (CHCl
3, SiO
2). The isolated oil was converted to the hydrochloride salt by treatment with Et
2O·HCl in EtOAc. Isolation by filtration provided 1.37 g (100%) of 2-(4-methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]amino]-6-methoxybenzo[b]thiophene
hydrochloride as a white solid. mp 126-130 °C.
1H NMR (DMSO-
d6) d 7.54 (d, J = 8.8 Hz, 2H), 7.48 (d, J = 2.2 Hz, 1H), 7.29 (d, J = 8.9 Hz, 1H),
6.92 (d, J = 8.8 Hz, 2H), 6.91 (dd, J = 8.9, 2.2 Hz, 1H), 6.73 (d, J = 8.9 Hz, 2H),
6.50 (d, J = 8.9 Hz, 2H), 4.21 (t, J = 4.7 Hz, 2H), 3.78 (s, 3H), 3.71 (s, 3H), 3.43-3.31
(m, 4H), 2.97-2.90 (m, 2H), 1.80-1.61 (m, 5H), 1.35 (m, 1H). FD mass spec: 488.
Anal. Calcd. for C
29H
34N
2O
3S•2.0 HCl: C, 62.03; H, 6.10; N, 4.99. Found: C, 61.79; H, 6.35; N, 5.27.
Example 3
2-(4-Hydroxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]amino]-6-hydroxybenzo[b]thiophene
Hydrochloride
[0090] To a solution of 2-(4-methoxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]amino]-6-methoxybenzo[b]thiophene
hydrochloride (0.70 g, 1.25 mmol) in 40 mL of anhydrous CH
2Cl
2 under N
2 10 °C was added BBr
3 (0.36 mL, 3.80 mmmol). The solution was allowed to gradually warm to room temperature
and stirred for a total of 6 h. The reaction was quenched by pouring the mixture into
an excess of sat. NaHCO
3 solution. The aqueous was then extracted several times with 5% EtOH/EtOAc. The organic
was combined and dried (Na
2SO
4) and then concentrated
in vacuo to a foam. The crude product was chromatographed (1-6% CH
3OH/CHCl
3) to provide 325 mg (49%) of 2-(4-hydroxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]amino]-6-hydroxybenzo[b]thiophene
as an oil. This material was converted to the hydrochloride salt by treatment with
Et
2O•HCl in EtOAc, and isolated as a white solid by filtration. Data for 2-(4-Hydroxyphenyl)-3-[N-[4-[2-(1-piperidinyl)ethoxy]phenyl]amino]-6-hydroxybenzo[b]thiophene
Hydrochloride: mp 140-150 °C.
1H NMR (DMSO-
d6) d 9.57 (s, 2H), 7.40 (d, J = 8.6 Hz, 2H), 7.19 (d, J = 10.1 Hz, 1H), 7.16 (d, J
= 2.0 Hz, 1H), 6.75 (dd, J = 10.1, 2.0 Hz, 1H), 6.70 (d, J = 8.6 Hz, 2H), 6.64 (d,
J = 8.8 Hz, 2H), 6.46 (d, J = 8.8 Hz, 2H), 4.21 (m, 2H), 3.50-3.30 (m, 4H), 3.01-2.95
(m, 2H), 1.81-1.63 (m, 5H), 1.38 (m, 1H). FD mass spec: 461.
Anal. Calcd. for C
27H
28N
2O
3S•1.5 HCl: C, 62.94; H, 5.77; N, 5.44. Found: C, 62.99; H, 5.88; N, 5.27.
[0091] In the examples illustrating the methods, a postmenopausal model was used in which
effects of different treatments upon circulating lipids were determined.
[0092] Seventy-five day old female Sprague Dawley rats (weight range of 200 to 225g) were
obtained from Charles River Laboratories (Portage, MI). The animals were either bilaterally
ovariectomized (OVX) or exposed to a Sham surgical procedure at Charles River Laboratories,
and then shipped after one week. Upon arrival, they were housed in metal hanging cages
in groups of 3 or 4 per cage and had
ad libitum access to food (calcium content approximately 0.5%) and water for one week. Room
temperature was maintained at 22.2° ± 1.7° C with a minimum relative humidity of 40%.
The photoperiod in the room was 12 hours light and 12 hours dark.
Dosing Regimen Tissue Collection. After a one week acclimation period (therefore, two weeks post-OVX) daily dosing
with test compound was initiated. 17a-ethynyl estradiol or the test compound were
given orally, unless otherwise stated, as a suspension in 1% carboxymethylcellulose
or dissolved in 20% cyclodextrin. Animals were dosed daily for 4 days. Following the
dosing regimen, animals were weighed and anesthetized with a ketamine: Xylazine (2:1,
V:V) mixture and a blood sample was collected by cardiac puncture. The animals were
then sacrificed by asphyxiation with CO
2, the uterus was removed through a midline incision, and a wet uterine weight was
determined.
Cholesterol Analysis. Blood samples were allowed to clot at room temperature for 2 hours, and serum was
obtained following centrifugation for 10 minutes at 3000 rpm. Serum cholesterol was
determined using a Boehringer Mannheim Diagnostics high performance cholesterol assay.
Briefly the cholesterol was oxidized to cholest-4-en-3-one and hydrogen peroxide.
The hydrogen peroxide was then reacted with phenol and 4-aminophenazone in the presence
of peroxidase to produce a p-quinone imine dye, which was read spectrophotemetrically
at 500 nm. Cholesterol concentration was then calculated against a standard curve.
The entire assay was automated using a Biomek Automated Workstation.
Uterine Eosinophil Peroxidase (EPO) Assay. Uteri were kept at 4° C until time of enzymatic analysis. The uteri were then homogenized
in 50 volumes of 50 mM Tris buffer (pH -8.0) containing 0.005% Triton X-100. Upon
addition of 0.01% hydrogen peroxide and 10 mM O-phenylenediamine (final concentrations)
in Tris buffer, increase in absorbance was monitored for one minute at 450 nm. The
presence of eosonophils in the uterus is an indication of estrogenic activity of a
compound. The maximal velocity of a 15 second interval was determined over the initial,
linear portion of the reaction curve.
Source of Compound: 17a-ethynyl estradiol was obtained from Sigma Chemical Co., St. Louis, MO.
Influence of Formula I Compounds on Serum Cholesterol and Determination of Agonist/Non-Agonist
Activity
[0093] Data presented in Table 1 below show comparative results among ovariectomized rats,
rats treated with 17a-ethynyl estradiol (EE
2; an orally available form of estrogen), and rats treated with certain compounds of
the instant invention. Although EE
2 caused a decrease in serum cholesterol when orally administered at 0.1 mg/kg/day,
it also exerted a stimulatory action on the uterus so that EE
2 uterine weight was substantially greater than the uterine weight of ovariectomized
test animals. This uterine response to estrogen is well recognized in the art.
[0094] Not only did the compounds of the instant invention generally reduce serum cholesterol
compared to the ovariectomized control animals, but uterine weight was only minimally
increased to slightly decreased with the majority of the formula compounds tested.
Compared to estrogenic compounds known in the art, the benefit of serum cholesterol
reduction without adversely affecting uterine weight is quite rare and desirable.
[0095] As is expressed in the data below, estrogenicity also was assessed by evaluating
the adverse response of eosinophil infiltration into the uterus. The compounds of
the instant invention did not cause any increase in the number of eosinophils observed
in the stromal layer of ovariectomized rats, while estradiol cause a substantial,
expected increase in eosinophil infiltration.
[0096] The data presented in Table 1 below reflects the response of 5 to 6 rats per treatment.
Table 1
| Compound No. |
Dose mg/kga |
Uterine Weight % Incb |
Uterine Eosinophil (Vmax)c |
Serum Cholest. % Dec.d |
| EE2e |
0.1 |
124.4* |
85.5* |
78.1* |
| Example 2 |
0.1 |
55.4* |
10.2 |
42.8* |
| |
1.0 |
89.5* |
12.9 |
46.4* |
| |
10. |
86.3* |
6.6 |
66.8* |
| Example 3 |
0.1 |
45.2* |
1.2 |
63.0* |
| |
1.0 |
39.4* |
4.5 |
51.7* |
| |
10.0 |
35.0* |
4.8 |
64.9* |
| a mg/kg PO |
| b Uterine Weight % increase versus the ovariectomized controls |
| c Eosinophil peroxidase Vmax |
| d Serum cholesterol decrease versus ovariectomized controls |
| e 17-a-Ethynyl-estradiol |
| * p<.05 |
[0097] In addition to the demonstrated benefits of the compounds of the instant invention,
the above data clearly demonstrate that compounds of Formula I are not estrogen mimetics.
Furthermore, no deleterious toxicological effects (for example, survival numbers)
were observed with any treatment.
Osteoporosis Test Procedure
[0098] Following the General Preparation Procedure,
infra, the rats are treated daily for 35 days (6 rats per treatment group) and sacrificed
by carbon dioxide asphyxiation on the 36th day. The 35 day time period is sufficient
to allow maximal reduction in bone density, measured as described herein. At the time
of sacrifice, the uteri are removed, dissected free of extraneous tissue, and the
fluid contents were expelled before determination of wet weight in order to confirm
estrogen deficiency associated with complete ovariectomy. Uterine weight is routinely
reduced about 75% in response to ovariectomy. The uteri are then placed in 10% neutral
buffered formalin to allow for subsequent histological analysis.
[0099] The right femurs are excised and digitilized x-rays generated and analyzed by an
image analysis program (NIH image) at the distal metaphysis. The proximal aspect of
the tibiae from these animals are also scanned by quantitative computed tomography.
[0100] In accordance with the above procedures, compounds of the instant invention and ethynyl
estradiol (EE
2) in 20% hydroxypropyl b-cyclodextrin are orally administered to test animals. Distal
femur metaphysis and proximal tibiae data results are reported as percent protection
relative to ovariectomy.
[0101] In summary, ovariectomy of the test animals caused a significant reduction in femur
density compared to intact, vehicle treated controls. Orally administered ethynyl
estradiol (EE
2) prevents this loss, but the risk of uterine stimulation with this treatment is ever-present.
[0102] The compounds of the instant invention also prevent bone loss in a general, dose-dependent
manner. Accordingly, the compounds of the instant invention are useful for the treatment
of osteoporosis, particularly caused by postmenopausal syndrome.